Calipers.



PATENTED OCT., 22|"1907.

A. THOMSEN.

CALIPERS. PPLIoAIIoH FILED mr 22. 19o6 CALIPERS.

Specification of Letters Patent.

Patented oct. 22, too?.

Application filed May 712, 1906. Serial No. 318,121.

To all whom it 'may concern:

Be it known that l, Acousfr Tiroirs-ns, a citizen of the United States,residing at Glendale. county ol' Queens, and State of New York, haveinvented certain new and useful Improvements in Calipers, ot' which thtlfollowing is a specification.

My invention relates to calipers or what may otherwise properly betermed gage mierotmfters designed for the use of machinists and otherartisans in taking acenrate and fine measurements, and has for au objectIhe production of an instrument of this elm-meter, which shall be simpleand quick-acting in its adjustment to inches or objects of widelyvarying sizes, and which shall also be capable of thereafter being movedto the smallest fractions thereof.

I will describe a caliper embodying my invention and then point out thenovel features thereof in claims. lIn the accompanying drawing Figure 1represents a side elevation of a caliper embodying my invention, thejaws4 being moved away from each other-to give a ;dis'tance of 2 inches.Fig. 2-is a longitudiiml section I Figi 3 is an end view o`f. Fig. l ona larger igs. 4 and 5 are sectional elevations taken on the line 4, 5,of Fig. 2, the former view showing the parts when in position for use intaking fine and accu- I l temeasurements, and the latter viewillustrating the "l their. position for use in taking measurementsinches. reference characters designate corresponding rtsLirall thefigures of the drawing.

Referring to said drawing, A designates my improved caliper', which ishere shown as comprising a bar a, y 2 w1iich-may be graduated on'one orboth sides into inches and fractions of inches of varying decimals, andrmdvble jaw b, movable on said bar a and preferably A f providedyith agraduation b1. The bar a is provided at one Gnd with extensions orfingers a2, which may correspondvvith similar extensions or fingers b2,on the end of the bar a, so that they will register when the movable jawis moved to its extreme position toward that. end of the bar The bar ais provided on its lower edge, preferably with a longitudinal groove al,in which a feather or spline b, on the movable jaw moves, which acts toassist in maintaining the latter in its proper relation with the bar aand the lower edges of the walls of the groove al, are provided withthreads adapted to be engaged by a Worm Wheel c, carried on one end of ashaft rl which rests within an opening c in the movable jaw. The shaft dpasses through an eccentrically arranged opening in a sleeve f, and hason its opposite end, a nut y, having a hub gl which is graduated, asshown, so that when the worm wheel is in engagement with the threads onthe bar a and rotation given to the nut g, each graduation on the hubwill move the movable jaw a very slight distance, according tothe pitchof the worm, thereby permitting of most minute adjustment ot' thecaliper.

lhe sleeve/is supported in an opening lt in the movable jaw h. and hasnt its onda nntf' so that. by giving rotation thereto in one directionor the other, the sleeve will be moved lo bring the worm wheel into orout of engagement. with the threads on the bar a, which, in be firstinstance permitsof gradual and accurateadjustment ol' the movable jan'(l, and in the other, instance permits it to be quickly moved along thebar a, to permit. of rapid and widely varying measurements being made.

ln order to give the worm wheel a tendency tofinclne to move toward andthe more flrml'y engage the threads on the bar a., I prefer to provide aspiral spring s for the sleevef, which is reduced to receive saidspring. One

, end of this spring is secured to the nut g and the other movement. 'ifthe shaft and otherwise insure accurate' enga-ement o1' the worm gearwith `the threads on the bar a, I may provide a tension spring t whichis placed in a recess in the movable jaw b adjacent the worm gear c andagainst which one' end of the spring will press. This arrangement servesto maintain the worm gear in the same longitudinal relation with themovable jaw at all times, and renders its adjustment more accurato,although, of course, the worm gear may be so accuL rately fitted betweenthe walls of the opening c as to make the use of the spring tumieeessary, in which event, I may dispense with The operation of myinvention may be understood from the foregoing, but the following briefdescription thereof may be deemed necessary. When it is desired toadjust the movable jaw by inches7 to use it upon objects of wid elyvarying sizes, the nut f will be turned to the left, which has theeffect of turning the sleeve f about one. half rotation, and, owing tothe eccentric relatioiiof the shaft d therewith, the latter will bemoved so as to bring its attached worm wheel out of engagement with thethreads on the bar a, permitting the movable jaw to be rapidly movedalong the bar b to the exact, or approximately the exact distancerequired. Should it, however, be required to secure a finer and moreaccurate adjustment of the movable 4jaw b, then the nut f l will beturned to the right, moving the sleeve f into such position as to bringthe worm wheel into engagement with the threads on the bar a, when, byrotation of the nut g in either direction, the movable jaw will becaused to' move along the bar a in a manner similar to such instrumentsnow in use, the graduation Of course, I may dispense with this springWhat I claim as my invention is: 1. A caliper or gage micrometercomprising n (iat bur having grnduntiuns on one or both of its sides andthreads along one edge' thereof nml having also n longitudinali groove`n movable jaw having;r n projection ndnptecl to slide in said groove inthe bur :1nd a graduation thereon in register with the yzraduatlons onthe bnr, :i wurm geur uurrieti hy said movable jun'. and un4 eccentricfor throwing?r said worm into and out of engagement with the threads outhe bnr-*to permit of grnrluul er rnlild adjustment of the uwvnhle jun'.

2. eulipnr nr enge micrometer comprising n bnr having grnihnlllens ouone or both of its sides und threads along one edge thereof :nul hnvinmralso n longitudinal groove, a uiuvnhle jun' lun-ine; n spline :Nluptedto slide in said gruute in the-hnr und :l grauluution thereon toregister.

wilh lhe grndnntions on the hurv n worin geur carried by Suid movnlllejeu', :in eurenilriu for throwing said worm into und out of eugugnuuniu'ilh the threads on the bar, :1nd n spring for keeping the eerentric inposition, whereby the worin is uorulnlly hehl out of engagement with theteeth un the han'.

ln testimony whereof I have signed luy name to this specification inlthe 1u'i.' -nee of lwu subscribed witnesses.

